Curability of patients with lymph node metastases from extremity soft-tissue sarcoma

Incidence and survival outcomes of patients with high-grade appendicular bone sarcoma and isolated regional lymph node metastasis: A national cohort database study

BACKGROUND

While distant metastases in primary bone sarcomas have been extensively studied, the impact of isolated regional lymph node (LN) metastasis on survival remains unknown. In patients with primary bone sarcomas, we sought to assess the prevalence of isolated regional LN metastasis and the survival of this population.

METHODS

A total of 6651 patients with histologically-confirmed high-grade osteosarcoma, Ewing sarcoma, or chondrosarcoma were retrieved from the SEER database. We defined four subgroups for our analysis: localized disease (N0 M0), isolated regional LN metastasis (N1 M0), isolated distant metastasis (N0 M1), and combined regional LN and distant metastasis (N1 M1). Disease-specific survival (DSS) was assessed using the Kaplan-Meier method.

RESULTS

Prevalence of isolated regional LN metastasis (N1 M0) was highest in Ewing sarcoma (27/1097; 3.3 %), followed by chondrosarcoma (18/1702; 1.4 %) and osteosarcoma (26/3740; 0.9 %). In all three histologies, patients with isolated regional LN metastasis had a worse 2-year, 5-year, and 10-year DSS than those with localized disease. Chondrosarcoma patients with isolated regional LN (N1 M0) metastasis had a significantly higher DSS in comparison to those with only distant metastasis (N0 M1) at the 5- and 10-year marks; for osteosarcoma and Ewing sarcoma, only a pattern towards higher survival was seen. Risk factors for presenting isolated regional LN metastasis included tumor location in lower-limb (OR = 2.01) or pelvis (OR = 2.49), diagnosis of Ewing sarcoma (OR = 2.98), and tumor >10 cm (OR = 1.96).

CONCLUSIONS

Isolated regional LN metastases in primary bone sarcomas is an infrequent presentation associated with worse survival than localized disease.

LEVEL OF EVIDENCE

III.

Differentiation of benign and metastatic lymph nodes in soft tissue sarcoma

Lymph node metastasis (LNM) occurs in less than 5% of soft tissue sarcoma (STS) patients and indicates an aggressive course of disease. Suspicious lymph nodes (LN) in staging imaging are a frequent topic of discussion in multidisciplinary tumor boards. Predictive markers are needed to facilitate stratification and improve treatment of STS patients. In this study, 56 STS patients with radiologically suspicious and subsequently histologically examined LN were reviewed. Patients with benign (n = 26) and metastatic (n = 30) LN were analyzed with regard to clinical, laboratory and imaging parameters. Patients with LNM exhibited significantly larger short axis diameter (SAD) and long axis diameter (LAD) vs. patients with benign LN (median 22.5 vs. 14 mm, p < 0.001 and median 29.5 vs. 21 mm, p = 0.003, respectively). Furthermore, the presence of central necrosis and high maximal standardized uptake value (SUVmax) in FDG-PET-CT scans were significantly associated with LNM (60 vs. 11.5% of patients, p < 0.001 and median 8.59 vs. 3.96, p = 0.013, respectively). With systemic therapy, a slight median size regression over time was observed in both metastatic and benign LN. Serum LDH and CRP levels were significantly higher in patients with LNM (median 247 vs. 187.5U/L, p = 0.005 and 1.5 vs. 0.55 mg/dL, p = 0.039, respectively). This study shows significant associations between LNM and imaging features as well as laboratory parameters of STS patients. The largest SAD, SUVmax in FDG-PET-CT scan, the presence of central necrosis, and high serum LDH level are the most important parameters to distinguish benign from metastatic LNs.

Metastatic clear cell sarcoma of the pancreas: A rare case report

BACKGROUND

Clear cell sarcoma (CCS) is a rare soft-tissue sarcoma. The most common metastatic sites for CCS are the lungs, bones and brain. CCS is highly invasive and mainly metastasizes to the lung, followed by the bone and brain; however, pancreatic metastasis is relatively rare.

CASE SUMMARY

We report on a rare case of CCS with pancreatic metastasis in a 47-year-old man. The patient had a relevant medical history 3 years ago, with abdominal pain as the main clinical manifestation. No abnormalities were observed on physical examination and the tumor was found on abdominal computed tomography. Based on the medical history and postoperative pathology, the patient was diagnosed with CCS with pancreatic metastasis. The patient was successfully treated with surgical interventions, including distal pancreatectomy and splenectomy.

CONCLUSION

This report summarizes the available treatment modalities for CCS and the importance of regular postoperative follow-up for patients with CCS.

Soft Tissue Sarcomas in Adolescents and Young Adults

Soft tissue sarcomas (STS) represent a heterogeneous group of extraskeletal mesenchymal tumors that affect individuals throughout the entire age continuum. Despite this pervasive influence, key differences exist in the presentation of these sarcomas across varying age groups that have prevented a more uniform approach to management. Notably, rhabdomyosarcoma (RMS) is more common in children, while most nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) subtypes are more prevalent in adults. Older patients with NRSTS appear to have more molecularly complex biology and often present with more advanced disease compared with children. Poorer outcome disparities are observed in older patients with RMS despite receiving similar treatment as younger patients. In this review, we highlight differences in epidemiology, biology, and management paradigms for pediatric and adult patients with STS and explore opportunities for a unified approach to enhance the care and outcomes within the AYA population.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

A machine learning-based model for clinical prediction of distal metastasis in chondrosarcoma: a multicenter, retrospective study

Background

The occurrence of distant metastases (DM) limits the overall survival (OS) of patients with chondrosarcoma (CS). Early diagnosis and treatment of CS remains a great challenge in clinical practice. The aim of this study was to investigate metastatic factors and develop a risk stratification model for clinicians' decision-making.

Methods

Six machine learning (ML) algorithms, including logistic regression (LR), plain Bayesian classifier (NBC), decision tree (DT), random forest (RF), gradient boosting machine (GBM) and extreme gradient boosting (XGBoost). A 10-fold cross-validation was performed for each model separately, multicenter data was used as external validation, and the best (highest AUC) model was selected to build the network calculator.

Results

A total of 1,385 patients met the inclusion criteria, including 82 (5.9%) patients with metastatic CS. Multivariate logistic regression analysis showed that the risk of DM was significantly higher in patients with higher pathologic grades, T-stage, N-stage, and non-left primary lesions, as well as those who did not receive surgery and chemotherapy. The AUC of the six ML algorithms for predicting DM ranged from 0.911-0.985, with the extreme gradient enhancement algorithm (XGBoost) having the highest AUC. Therefore, we used the XGB model and uploaded the results to an online risk calculator for estimating DM risk.

Conclusions

In this study, combined with adequate SEER case database and external validation with data from multicenter institutions in different geographic regions, we confirmed that CS, T, N, laterality, and grading of surgery and chemotherapy were independent risk factors for DM. Based on the easily available clinical risk factors, machine learning algorithms built the XGB model that predicts the best outcome for DM. An online risk calculator helps simplify the patient assessment process and provides decision guidance for precision medicine and long-term cancer surveillance, which contributes to the interpretability of the model.

Fine-Needle Aspiration of Sarcomas Metastatic to Lymph Nodes: A Cytomorphologic Study over a 10-Year Period

INTRODUCTION

Metastasis of sarcomas to lymph nodes is an uncommon event in its natural history. We aimed to present our experience with fine-needle aspiration (FNA) of metastatic sarcomas to lymph nodes over a 10-year period.

MATERIAL AND METHODS

The cytopathology archives were searched for FNA of lymph nodes involved by metastatic sarcomas. Available clinicopathologic data were recorded. All slides were retrieved and reviewed.

RESULTS

Thirty-three lymph nodes, from 30 patients, with metastatic soft tissue sarcomas were identified. The lymph node metastases occurred in 16 males and 14 females (median age, 56 years). The size of the lymph nodes ranged from 1.2 to 7.5 cm (median size, 2.9 cm). The inguinal lymph nodes were the most commonly involved nodes, followed by thoracic and cervical neck nodes. The most common metastatic soft tissue sarcoma encountered was Kaposi sarcoma (n = 7, 23.3%), followed by angiosarcoma (n = 6, 20%) and rhabdomyosarcoma (n = 6, 20%). The most common site of primary soft tissue sarcoma was the head and neck (n = 8, 26.6%), followed by lower extremity (n = 7, 23.3%). The initial diagnosis of sarcoma was established in 6 cases. Seventen patients had metachronous involvement of lymph nodes, while the remaining patients had synchronous involvement. Seventen patients died of disease, and the survival after lymph node metastasis ranged from 1 to 43 months.

CONCLUSION

FNA is an accurate and effective method in the diagnosis of metastatic sarcoma to lymph nodes. Knowledge of clinical findings and primary tumor diagnosis along with careful assessment of the cytomorphology is extremely helpful for an accurate diagnosis of metastases.

Clear cell sarcoma: state-of-the art and perspectives

INTRODUCTION

Clear cell sarcoma (CCS) is an ultrarare soft tissue sarcoma (STS) with a poor prognosis due to its propensity to metastasize and its low chemosensitivity. The standard treatment of localized CCS consists of wide surgical excision with or without additive radiotherapy. However, unresectable CCS is generally treated with conventional systemic therapies available for treatment of STS despite the weak scientific evidence to support its use.

AREAS COVERED

In this review, we discuss the clinicopathologic characteristics of CSS, as well as the current treatment landscape and future therapeutic approaches.

EXPERT OPINION

The current treatment strategy of advanced CCSs, based on STSs regimens, shows a lack of effective options. Combination therapiesin particular, the association of immunotherapy and TKIs, represent a promising approach. Translational studies are needed in order to decipher the regulatory mechanisms involved in the oncogenesis of this ultrarare sarcoma and identify potential molecular targets.

Practice Pattern Variability in the Management of Regional Lymph Node Metastasis in Extremity and Trunk Soft Tissue Sarcoma: A Survey of the Society of Surgical Oncology and Musculoskeletal Tumor Society Membership

BACKGROUND

Regional lymph node metastasis in extremity and trunk soft tissue sarcoma (ETSTS) is rare with no standardized management. We sought to determine management patterns for regional lymph node metastasis in ETSTS.

METHODS

A survey regarding the management of ETSTS lymph node metastasis was distributed to the membership of the Musculoskeletal Tumor Society (MSTS) and the Society of Surgical Oncology (SSO) in January 2022. The survey queried the type of training (surgical oncology, orthopedic oncology), details of their practice setting, and management decisions of hypothetical ETSTS scenarios that involved potential or confirmed lymph node metastasis.

RESULTS

The survey was distributed to 349 MSTS members (open rate of 63%, completion rate 21%) and 3026 SSO members (open rate of 55%, completion rate 4.7%) and was completed by 214 respondents, of whom 73 (34.1%) and 141 (65.9%) were orthopedic oncology and surgical oncology fellowship-trained, respectively. The majority of respondents practiced in an academic setting (n = 171, 79.9%) and treat >10 extremity sarcoma cases annually (n = 138, 62.2%). In scenarios with confirmed nodal disease for clear cell and epithelioid sarcoma, surgical oncologists were inclined to perform lymphadenectomy, while orthopedic oncologists were inclined to offer targeted lymph node excision with adjuvant radiation (p < 0.001). There was heterogeneity of responses regarding the management of nodal disease regardless of training background.

CONCLUSION

Self-reported management of nodal disease in ETSTS was variable among respondent groups with differences and similarities based on training background. These data highlight the variability of practice for nodal disease management and the need for consensus-based guidelines.

Sentinel Lymph Node Biopsy for Extremity and Truncal Soft Tissue Sarcomas: A Systematic Review of the Literature

BACKGROUND

Regional lymph node metastasis (RLNM) occurs infrequently in patients with soft tissue sarcoma (STS), although certain STS subtypes have a higher propensity for RLNM. The identification of RLNM has significant implications for staging and prognosis; however, the precise impact of node-positive disease on patient survival remains a topic of controversy. Although the benefits of sentinel lymph node biopsy (SLNB) are well documented in patients with melanoma and breast cancer, whether this procedure offers a benefit in STS is controversial.

METHODS

A systematic literature search was performed and articles reviewed to determine if SLNB in patients with extremity/truncal STS impacts disease-free or overall survival.

RESULTS

Six studies were included. Rates of sentinel lymph node positivity were heterogeneous (range 4.3-50%). The impact of SLNB on patient outcomes remains unclear. The overall quality of available evidence was low, as assessed by the Grading of Recommendations, Assessment, Development, and Evaluation system.

CONCLUSIONS

The literature addressing the impact of nodal basin evaluation on the staging and management of patients with extremity/truncal STS is confounded by heterogeneous patient cohorts and clinical practices. Multicenter prospective studies are warranted to determine the true incidence of RLNM and whether SLNB could benefit patients with clinically occult RLNM at diagnosis.

Lymph node metastases in paediatric and young adult patients with non-rhabdomyosarcoma soft tissue sarcoma (NRSTS): Findings from Children's Oncology Group (COG) study ARST0332

PURPOSE

The aim of this paper is to better define the clinical features and outcomes of young patients with non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) with regional and distant lymph node (LN) metastases treated in a standardised fashion, we analysed LN involvement in COG study ARST0332, which evaluated a risk-based treatment strategy for young patients with all stages of NRSTS.

PATIENTS AND METHODS

Patients <30 years old with newly diagnosed NRSTS and LN metastases enrolled on ARST0332 were studied. Regional LN sampling was required for those with epithelioid sarcoma, clear cell sarcoma or clinically/radiographically enlarged LNs. Tumour features and extent of pre-enrolment resection determined treatment, including chemotherapy, radiotherapy, and delayed surgery. Recommendations for LN metastases included LN dissection at the time of primary tumour resection and dose-adapted radiotherapy based on extent of LN resection.

RESULTS

Twenty of 529 eligible and evaluable ARST0332 patients with NRSTS had LN metastases; epithelioid sarcoma had the highest incidence (18%, 5 of 28). Pre-treatment imaging identified LN enlargement in 19 of 20 patients; 1 had no pre-treatment LN imaging. At 6.9 years median follow-up for surviving patients, 5-year overall survival was 85.7% (95% CI: 33.4%, 97.9%) for seven patients with isolated LN metastases and 15.4% (95% CI: 2.5%, 38.8%) for 13 patients with additional extranodal metastases. LN recurrence occurred in only one patient without LNs sampled at initial diagnosis.

CONCLUSION

LN metastases occur in about 4% of paediatric/young adult NRSTS, are limited to a few histologic subtypes, and are rare in patients who did not have clinical or imaging evidence of lymphadenopathy, suggesting that biopsies of non-enlarged LNs are not necessary to identify occult involvement. Patients with isolated LN metastases have high 5-year overall survival (∼85%) and should be treated with curative intent.

CLINICALTRIALS

GOV REGISTRY NO

NCT00346164.

Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma

Although survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites.

Early distinction of lymph node metastasis in patients with soft tissue sarcoma and individualized survival prediction using the online available nomograms: A population-based analysis

Background

The presence of metastatic tumor cells in regional lymph nodes is considered as a significant indicator for inferior prognosis. This study aimed to construct some predictive models to quantify the probability of lymph node metastasis (LNM) and survival rate of patients with soft tissue sarcoma (STS) with LNM.

Methods

Research data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2017, and data of patients with STS from our medical institution were collected to form an external testing set. Univariate and multivariate logistic regression analyses were used to determine the independent risk factors for developing LNM. On the basis of the identified variables, we developed a diagnostic nomogram to predict the risk of LNM in patients with STS. Those patients with STS presenting with LNM were retrieved to build a cohort for identifying the independent prognostic factors through univariate and multivariate Cox regression analysis. Then, two nomograms incorporating the independent prognostic predictors were developed to predict the overall survival (OS) and cancer-specific survival (CSS) for patients with STS with LNM. Kaplan-Meier (K-M) survival analysis was conducted to study the survival difference. Moreover, validations of these nomograms were performed by the receiver operating characteristic curves, the area under the curve, calibration curves, and the decision curve analysis (DCA).

Results

A total of 16,601 patients with STS from the SEER database were enrolled in our study, of which 659 (3.97%) had LNM at the initial diagnosis. K-M survival analysis indicated that patients with LNM had poorer survival rate. Sex, histology, primary site, grade, M stage, and T stage were found to be independently related with development of LNM in patients with STS. Age, grade, histology, M stage, T stage, chemotherapy, radiotherapy, and surgery were identified as the independent prognostic factors for OS of patients with STS with LNM, and age, grade, M stage, T stage, radiotherapy, and surgery were determined as the independent prognostic factors for CSS. Subsequently, we constructed three nomograms, and their online versions are as follows: https://tyxupup.shinyapps.io/probabilityofLNMforSTSpatients/, https://tyxupup.shinyapps.io/OSofSTSpatientswithLNM/, and https://tyxupup.shinyapps.io/CSSofSTSpatientswithLNM/. The areas under the curve (AUCs) of diagnostic nomogram were 0.839 in the training set, 0.811 in the testing set, and 0.852 in the external testing set. For prognostic nomograms, the AUCs of 24-, 36-, and 48-month OS were 0.820, 0.794, and 0.792 in the training set and 0.759, 0.728, and 0.775 in the testing set, respectively; the AUCs of 24-, 36-, and 48-month CSS were 0.793, 0.777, and 0.775 in the training set and 0.775, 0.744, and 0.738 in the testing set, respectively. Furthermore, calibration curves suggested that the predicted values were consistent with the actual values. For the DCA, our nomograms showed a superior net benefit across a wider scale of threshold probabilities for the prediction of risk and survival rate for patients with STS with LNM.

Conclusion

These newly proposed nomograms promise to be useful tools in predicting the risk of LNM for patients with STS and individualized survival prediction for patients with STS with LNM, which may help to guide clinical practice.

Sentinel Lymph Node Biopsy and Formal Lymphadenectomy for Soft Tissue Sarcoma: A Single Center Experience of 86 Consecutive Cases

BACKGROUND

Lymph node metastases (LNMs) are rare in patients with soft tissue sarcoma (STS), and there is limited evidence to guide clinical management. We describe our experience with sentinel lymph node biopsy (SLNB) and lymphadenectomy in STS patients.

METHODS

A single-center, retrospective review was performed for patients with STS treated with SLNB and/or lymphadenectomy from 1994 to 2018. Clinicopathologic characteristics, multimodality treatment, regional/distant recurrence-free survival (RFS), and overall survival (OS) were examined.

RESULTS

Eighty-six patients underwent SLNB (n = 34) and/or lymphadenectomy (n = 60) for STS. The most frequent histologic subtypes were epithelioid, clear cell, and undifferentiated pleomorphic sarcoma. Eight of 34 (23.5%) patients had a positive SLNB with 5-year OS of 71.4% compared with 71.9% for those with a negative SLNB. Eight of the 26 SLN-negative patients (30.8%) eventually developed nodal recurrence (n = 2) and/or (n = 6) distant metastasis with an estimated 5-year OS of 50%. Of patients undergoing lymphadenectomy, estimated 5-year OS was 44.6% and median RFS was 12 months. Eight (13.3%) had distant disease at time of lymphadenectomy, 20 (33.3%) developed distant recurrence after lymphadenectomy, and 6 (10%) developed regional-only recurrence. Patients with regional-only recurrence after lymphadenectomy had an estimated 5-year OS of 66.7% compared with 29.1% for those who recurred distantly.

CONCLUSIONS

Patients with positive SLNB had similar survival to those with negative SLNB. Lymphadenectomy for isolated nodal disease is associated with poor RFS but reasonable 5-year OS when recurrence is regional-only. In STS, regional disease appears clinically distinct from distant metastatic disease and has better outcomes.

The Association of Metastasis Pattern and Management of Metastatic Disease with Oncological Outcomes in Patients with Malignant Peripheral Nerve Sheath Tumors: A Multicenter Cohort Study

Simple Summary

Around 40% of patients with MPNSTs develop distant metastasis (DM) within five years. Identification of MPNST patients more likely to develop DM and the identification of prognostic factors after DM diagnosis may guide clinical decision-making and may result in a better balance between quantity and quality of life. This study aimed to identify clinicopathologic and treatment-related factors associated with the development of DM and with overall survival (OS) after DM diagnosis. NF1, high grade, tumor size, triton and R2 resections were independent risk factors for the development of DM. This is the first study that reveals that NF1 status is also independently associated with worse survival after DM diagnosis with a median survival difference of more than 6 months between NF1 and no-NF1 patients.

Abstract

Purpose: This multicenter cohort study aimed to identify clinicopathologic and treatment-related factors associated with the development of distant metastasis (DM) and with overall survival (OS) after DM diagnosis in patients with malignant peripheral nerve sheath tumors (MPNST). Methods: All patients diagnosed with primary MPNST from 1988 to 2019 who were surgically treated for the primary tumor were included. Multivariable Cox regression analyses were performed to identify factors associated with DM and OS after DM diagnosis. Results: A total of 383 patients were included in this analysis, of which 150 developed metastatic disease. No differences in clinicopathologic characteristics and clinical outcome were found between patients with synchronous and metachronous DM. Neurofibromatosis type 1 (NF1), high grade, tumor size, triton and R2 resections were independent risk factors for the development of DM. NF1 and more than two metastasis sites were independently associated with worse OS after DM diagnosis. Metastasectomy, chemotherapy and the metastatic site category ‘other’ were associated with prolonged survival after DM diagnosis. Conclusions: This analysis provides important insights into clinicopathologic and treatment factors associated with outcomes in metastatic MPNST. Moreover, NF1-status is associated with a higher risk of DM; it is also independently associated with worse survival in metastatic MPNST.

Comparison of the 7th and 8th version of the AJCC classification system for soft tissue sarcomas of extremities and trunk in patients with localised, intermediate or high-grade disease treated at European tertiary sarcoma centres

BACKGROUND

The updated 8th version of the AJCC-staging system for soft tissue sarcomas (STS) has been criticised for omitting tumour depth as category-defining variable and eventually not improving prognostic accuracy in comparison to the 7th version. This study aimed at investigating the prognostic accuracy of both AJCC-versions in STS-patients treated at European tertiary sarcoma centres.

METHODS

1032 patients (mean age: 60.7 ± 16.3 years; 46.0% [n = 475] females; median follow-up: 38.6 months), treated at five tertiary sarcoma centres for localised, intermediate or high-grade STS of extremities and trunk were retrospectively included. Uni- and multivariate Cox-regression models and Harrell's C-indices were calculated to analyse prognostic factors for overall survival (OS) and assess prognostic accuracy.

RESULTS

In univariate analysis, prognostic accuracy for OS was comparable for both AJCC-versions (C-index: 0.620 [8th] vs. 0.614 [7th]). By adding margins, age, gender, and histology to the multivariate models, prognostic accuracy of both versions could be likewise improved (C-index: 0.714 [8th] vs. 0.705 [7th]). Moreover, tumour depth did not significantly contribute to prognostic accuracy of the 8th version's multivariate model (C-index for both models: 0.714). Stratification into four main T-stages based on tumour size only, as implemented in the 8th version, significantly improved prognostic accuracy between each category. However, T-stages as defined in the 7th version had poorer discriminatory power (C-index: 0.625 [8th] vs. 0.582 [7th]).

CONCLUSION

Both AJCC-versions perform equally well regarding prognostic accuracy. Yet, simplification of the 8 ^th version by omitting tumour depth as T-stage-defining parameter, whilst emphasizing the importance of tumour size, should be considered advantageous.

Extraskeletal myxoid chondrosarcoma: a case report with adjuvant intraoperative treatment

Extraskeletal myxoid chondrosarcoma is a rare form of malignant mesenchymal neoplasm mainly localized into the limbs, particularly in the thigh and popliteal fossa. It has been classified as a low-grade sarcoma so far, but it shows a tendency to relapse and metastasize. In the early stage of disease, surgery represents the only chance of cure. In case of diffuse metastatic disease, systemic chemotherapy with anthracyclines is the standard of care. In this paper, we present a case of a patient affected by this rare disease and the analysis of radiological, surgical and histopathological aspects.